Audiophilepure

https://www.stereophile.com/content/nordost-qnet7-reclocking-network-switch

The QNet has one oscillator—one clock; the QNet7 has two. The two layers of ports 1–5 are handled by a single clock, while those of port 6 are separated into two dedicated circuits, one for each layer, and handled by two clocks. Port 7, in turn, uses a single clock.Why does an Ethernet switch need clocks? “When the Ethernet signal arrives at the QNet7, it is undone, so to speak, and redone,” Bonotto explained. “The bits (information) are transformed, encapsulated, and made into symbols so they can travel down the line in a more efficient and noise-proof way. Rather than send the packets down the cable directly, they are forwarded to the PHY unit, whose role is to take those packets and ‘line code’ them. Essentially, this makes the data more immune to noise. The whole process becomes more reliable. When the symbols arrive, everything must be de-encapsulated, as it were, and transformed back into bits. Then it gets routed and re-encapsulated and resent out on the other port. For this to happen, you need a clock base—a timing base. It’s the oscillator that makes it possible.”